Ghost Writer (2015)

Both are about best-selling female novelists loved around the country. They both focus on successful and strong female leads. Both female novelist-protagonists have loyal maids/ caretakers ready to die and sacrifice themselves for them.

Both are psychological, but Tsumi to Batsu in a more dark and probably less "human" way. They deal with opposite issues (celebrity vs. troubled youth) but there's a lot of conspiracy in both dramas. Plus the cast: Tanaka Tetsushi plays a kind of similar role, there's also Mizukawa Asami in both.